The present invention relates to a method for producing a fertilizer and soil conditioner from a shredded or particulate cellulosic material, and, more particularly, it relates to a method for nitration of waste paper to produce a fertilizer and soil conditioner.
Materials such as sawdust and newspaper are essentially cellulose. When added to soil, these materials increase the moisture holding capacity of the soil and improve its physical condition or tilth. The principal problem associated with the incorporation of shredded paper, sawdust, etc. in soil is the high carbon to nitrogen ratio created in the soil. The reason for this condition is that when soil bacteria use cellulosic material as an energy substrate, the bacteria also deplete the soil of available nitrogen thereby depriving plants of nitrogen to such an extent that a nitrogen deficiency occurs in plants. It would, therefore, be desirable to supply make-up nitrogen along with such soil conditioners.
Nitric acid reacts with cellulose to form cellulose nitrate or nitrocellulose. The traditional process for production of nitrocellulose is not suitable for the production of a fertilizer from waste paper. In the classical method for the production of nitrocellulose, concentrated sulfuric acid is ordinarily present to take up the water which is produced in the reaction, as follows: ##STR1## In this reaction, the average composition of the acids used is 21% HNO.sub.3 and 63% H.sub.2 SO.sub.4. While this is true of known nitration reactions, it has been found that in the production of a fertilizer, the use of sulfuric acid is undesirable since high amounts of bases such as KOH or Ca(OH).sub.2 would be needed to neutralize the sulfuric acid. Since all of the added chemicals would appear in the final product, high amounts of sulfur in such compounds as K.sub.2 SO.sub.4 and CaSO.sub.4, would be present as a result of neutralization. This is undesirable because sulfur is required in only minor amounts for plant nutrition and is acid forming in soil.
Likewise, in the traditional process, finished nitrocellulose is washed with copious amounts of water and may have a chemical stabilizer added. However, this means that an acidic product is produced which could adversely effect plant growth or result in product degradation. Finally, the traditional process for producing nitrated cellulose products results in materials containing varying amounts of nitrogen for differing uses:
10.7-11.2% N--celluloid PA1 11.8-12.3% N--lacquers PA1 12.6-13.5% N--explosives
From the standpoint of fertilizer production such high amounts of nitrogen content are not desired because of increased flammability and/or explosivity hazard.
Still it would be highly desirable to be able to produce a nitrogen fertilizer from waste paper. This would have the advantage of providing an ecologically sound disposal of such cellulosic materials and the agricultural benefit of providing a cheap and effective source of fertilizer.
Accordingly, the need exists for a method for producing a fertilizer from shredded or particulate cellulosic material such as waste paper by a nitration reaction which has none of the disadvantages of the traditional process for production of nitrocellulose.